| Message ID | 20241016-fuse-uring-for-6-10-rfc4-v4-0-9739c753666e@ddn.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | fuse: fuse-over-io-uring | expand |
Please note that this is a preview only to show the current status. V5 should follow soon to separate the headers into its own buffer. I actually hope that this v4 is the last RFC version. Thanks, Bernd
On 2024-10-15 17:05, Bernd Schubert wrote: [...] > > The corresponding libfuse patches are on my uring branch, > but need cleanup for submission - will happen during the next > days. > https://github.com/bsbernd/libfuse/tree/uring > > Testing with that libfuse branch is possible by running something > like: > > example/passthrough_hp -o allow_other --debug-fuse --nopassthrough \ > --uring --uring-per-core-queue --uring-fg-depth=1 --uring-bg-depth=1 \ > /scratch/source /scratch/dest > > With the --debug-fuse option one should see CQE in the request type, > if requests are received via io-uring: > > cqe unique: 4, opcode: GETATTR (3), nodeid: 1, insize: 16, pid: 7060 > unique: 4, result=104 > > Without the --uring option "cqe" is replaced by the default "dev" > > dev unique: 4, opcode: GETATTR (3), nodeid: 1, insize: 56, pid: 7117 > unique: 4, success, outsize: 120 Hi Bernd, I applied this patchset to io_uring-6.12 branch with some minor conflicts. I'm running the following command: $ sudo ./build/example/passthrough_hp -o allow_other --debug-fuse --nopassthrough \ --uring --uring-per-core-queue --uring-fg-depth=1 --uring-bg-depth=1 \ /home/vmuser/scratch/source /home/vmuser/scratch/dest FUSE library version: 3.17.0 Creating ring per-core-queue=1 sync-depth=1 async-depth=1 arglen=1052672 dev unique: 2, opcode: INIT (26), nodeid: 0, insize: 104, pid: 0 INIT: 7.40 flags=0x73fffffb max_readahead=0x00020000 INIT: 7.40 flags=0x4041f429 max_readahead=0x00020000 max_write=0x00100000 max_background=0 congestion_threshold=0 time_gran=1 unique: 2, success, outsize: 80 I created the source and dest folders which are both empty. I see the following in dmesg: [ 2453.197510] uring is disabled [ 2453.198525] uring is disabled [ 2453.198749] uring is disabled ... If I then try to list the directory /home/vmuser/scratch: $ ls -l /home/vmuser/scratch ls: cannot access 'dest': Software caused connection abort And passthrough_hp terminates. My kconfig: CONFIG_FUSE_FS=m CONFIG_FUSE_PASSTHROUGH=y CONFIG_FUSE_IO_URING=y I'll look into it next week but, do you see anything obviously wrong?
Hi David, On 10/21/24 06:06, David Wei wrote: > [You don't often get email from dw@davidwei.uk. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] > > On 2024-10-15 17:05, Bernd Schubert wrote: > [...] >> ... > Hi Bernd, I applied this patchset to io_uring-6.12 branch with some > minor conflicts. I'm running the following command: > > $ sudo ./build/example/passthrough_hp -o allow_other --debug-fuse --nopassthrough \ > --uring --uring-per-core-queue --uring-fg-depth=1 --uring-bg-depth=1 \ > /home/vmuser/scratch/source /home/vmuser/scratch/dest > FUSE library version: 3.17.0 > Creating ring per-core-queue=1 sync-depth=1 async-depth=1 arglen=1052672 > dev unique: 2, opcode: INIT (26), nodeid: 0, insize: 104, pid: 0 > INIT: 7.40 > flags=0x73fffffb > max_readahead=0x00020000 > INIT: 7.40 > flags=0x4041f429 > max_readahead=0x00020000 > max_write=0x00100000 > max_background=0 > congestion_threshold=0 > time_gran=1 > unique: 2, success, outsize: 80 > > I created the source and dest folders which are both empty. > > I see the following in dmesg: > > [ 2453.197510] uring is disabled > [ 2453.198525] uring is disabled > [ 2453.198749] uring is disabled > ... > > If I then try to list the directory /home/vmuser/scratch: > > $ ls -l /home/vmuser/scratch > ls: cannot access 'dest': Software caused connection abort > > And passthrough_hp terminates. > > My kconfig: > > CONFIG_FUSE_FS=m > CONFIG_FUSE_PASSTHROUGH=y > CONFIG_FUSE_IO_URING=y > > I'll look into it next week but, do you see anything obviously wrong? thanks for testing it! I just pushed a fix to my libfuse branches to avoid the abort for -EOPNOTSUPP. It will gracefully fall back to /dev/fuse IO now. Could you please use the rfcv4 branch, as the plain uring branch will soon get incompatible updates for rfc5? https://github.com/bsbernd/libfuse/tree/uring-for-rfcv4 The short answer to let you enable fuse-io-uring: echo 1 >/sys/module/fuse/parameters/enable_uring (With that the "uring is disabled" should be fixed.) The long answer for Miklos and others IOCTL removal introduced a design issue, as now fuse-client (kernel) does not know if fuse-server/libfuse wants to set up io-uring communication. It is not even possible to forbid FUSE_URING_REQ_FETCH after FUSE_INIT reply, as io-uring is async. What happens is that fuse-client (kernel) receives all FUSE_URING_REQ_FETCH commands only after FUSE_INIT reply. And that although FUSE_URING_REQ_FETCH is send out from libuse *before* replying to FUSE_INIT. I had also added a comment for that into the code. And the other issue is that libfuse now does not know if kernel supports fuse-io-uring. That has some implications - libfuse cannot write at start up time a clear error message like "Kernel does not support fuse-over-io-uring, falling back to /dev/fuse IO" - In the fallback code path one might want to adjust number of libfuse /dev/fuse threads if io-uring is not supported - with io-uring typically one thread might be sufficient - to handle FUSE_INTERRUPT. My suggestion is that we introduce the new FUSE_URING_REQ_REGISTER (or replace FUSE_URING_REQ_FETCH with that) and then wait in fuse-server for completion of that command before sending out FUSE_URING_REQ_FETCH. Thanks, Bernd
On 2024-10-21 04:47, Bernd Schubert wrote: > Hi David, > > On 10/21/24 06:06, David Wei wrote: >> [You don't often get email from dw@davidwei.uk. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] >> >> On 2024-10-15 17:05, Bernd Schubert wrote: >> [...] >>> > > ... > >> Hi Bernd, I applied this patchset to io_uring-6.12 branch with some >> minor conflicts. I'm running the following command: >> >> $ sudo ./build/example/passthrough_hp -o allow_other --debug-fuse --nopassthrough \ >> --uring --uring-per-core-queue --uring-fg-depth=1 --uring-bg-depth=1 \ >> /home/vmuser/scratch/source /home/vmuser/scratch/dest >> FUSE library version: 3.17.0 >> Creating ring per-core-queue=1 sync-depth=1 async-depth=1 arglen=1052672 >> dev unique: 2, opcode: INIT (26), nodeid: 0, insize: 104, pid: 0 >> INIT: 7.40 >> flags=0x73fffffb >> max_readahead=0x00020000 >> INIT: 7.40 >> flags=0x4041f429 >> max_readahead=0x00020000 >> max_write=0x00100000 >> max_background=0 >> congestion_threshold=0 >> time_gran=1 >> unique: 2, success, outsize: 80 >> >> I created the source and dest folders which are both empty. >> >> I see the following in dmesg: >> >> [ 2453.197510] uring is disabled >> [ 2453.198525] uring is disabled >> [ 2453.198749] uring is disabled >> ... >> >> If I then try to list the directory /home/vmuser/scratch: >> >> $ ls -l /home/vmuser/scratch >> ls: cannot access 'dest': Software caused connection abort >> >> And passthrough_hp terminates. >> >> My kconfig: >> >> CONFIG_FUSE_FS=m >> CONFIG_FUSE_PASSTHROUGH=y >> CONFIG_FUSE_IO_URING=y >> >> I'll look into it next week but, do you see anything obviously wrong? > > > thanks for testing it! I just pushed a fix to my libfuse branches to > avoid the abort for -EOPNOTSUPP. It will gracefully fall back to > /dev/fuse IO now. > > Could you please use the rfcv4 branch, as the plain uring > branch will soon get incompatible updates for rfc5? > > https://github.com/bsbernd/libfuse/tree/uring-for-rfcv4 > > > The short answer to let you enable fuse-io-uring: > > echo 1 >/sys/module/fuse/parameters/enable_uring > > > (With that the "uring is disabled" should be fixed.) Thanks, using this branch fixed the issue and now I can see the dest folder mirroring that of the source folder. There are two issues I noticed: [63490.068211] ---[ end trace 0000000000000000 ]--- [64010.242963] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:330 [64010.243531] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 11057, name: fuse-ring-1 [64010.244092] preempt_count: 1, expected: 0 [64010.244346] RCU nest depth: 0, expected: 0 [64010.244599] 2 locks held by fuse-ring-1/11057: [64010.244886] #0: ffff888105db20a8 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_enter+0x900/0xd80 [64010.245476] #1: ffff88810f941818 (&fc->lock){+.+.}-{2:2}, at: fuse_uring_cmd+0x83e/0x1890 [fuse] [64010.246031] CPU: 1 UID: 0 PID: 11057 Comm: fuse-ring-1 Tainted: G W 6.11.0-10089-g0d2090ccdbbe #2 [64010.246655] Tainted: [W]=WARN [64010.246853] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [64010.247542] Call Trace: [64010.247705] <TASK> [64010.247860] dump_stack_lvl+0xb0/0xd0 [64010.248090] __might_resched+0x2f8/0x510 [64010.248338] __kmalloc_cache_noprof+0x2aa/0x390 [64010.248614] ? lockdep_init_map_type+0x2cb/0x7b0 [64010.248923] ? fuse_uring_cmd+0xcc2/0x1890 [fuse] [64010.249215] fuse_uring_cmd+0xcc2/0x1890 [fuse] [64010.249506] io_uring_cmd+0x214/0x500 [64010.249745] io_issue_sqe+0x588/0x1810 [64010.249999] ? __pfx_io_issue_sqe+0x10/0x10 [64010.250254] ? io_alloc_async_data+0x88/0x120 [64010.250516] ? io_alloc_async_data+0x88/0x120 [64010.250811] ? io_uring_cmd_prep+0x2eb/0x9f0 [64010.251103] io_submit_sqes+0x796/0x1f80 [64010.251387] __do_sys_io_uring_enter+0x90a/0xd80 [64010.251696] ? do_user_addr_fault+0x26f/0xb60 [64010.251991] ? __pfx___do_sys_io_uring_enter+0x10/0x10 [64010.252333] ? __up_read+0x3ba/0x750 [64010.252565] ? __pfx___up_read+0x10/0x10 [64010.252868] do_syscall_64+0x68/0x140 [64010.253121] entry_SYSCALL_64_after_hwframe+0x76/0x7e [64010.253444] RIP: 0033:0x7f03a03fb7af [64010.253679] Code: 45 0f b6 90 d0 00 00 00 41 8b b8 cc 00 00 00 45 31 c0 41 b9 08 00 00 00 41 83 e2 01 41 c1 e2 04 41 09 c2 b8 aa 01 00 00 0f 05 <c3> a8 02 74 cc f0 48 83 0c 24 00 49 8b 40 20 8b 00 a8 01 74 bc b8 [64010.254801] RSP: 002b:00007f039f3ffd08 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa [64010.255261] RAX: ffffffffffffffda RBX: 0000561ab7c1ced0 RCX: 00007f03a03fb7af [64010.255695] RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000009 [64010.256127] RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000008 [64010.256556] R10: 0000000000000000 R11: 0000000000000246 R12: 0000561ab7c1d7a8 [64010.256990] R13: 0000561ab7c1da00 R14: 0000561ab7c1d520 R15: 0000000000000001 [64010.257442] </TASK> If I am already in dest when I do the mount using passthrough_hp and then e.g. ls, it hangs indefinitely even if I kill passthrough_hp.
On 10/21/24 22:57, David Wei wrote: > On 2024-10-21 04:47, Bernd Schubert wrote: >> Hi David, >> >> On 10/21/24 06:06, David Wei wrote: >>> [You don't often get email from dw@davidwei.uk. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] >>> >>> On 2024-10-15 17:05, Bernd Schubert wrote: >>> [...] >>>> >> >> ... >> >>> Hi Bernd, I applied this patchset to io_uring-6.12 branch with some >>> minor conflicts. I'm running the following command: >>> >>> $ sudo ./build/example/passthrough_hp -o allow_other --debug-fuse --nopassthrough \ >>> --uring --uring-per-core-queue --uring-fg-depth=1 --uring-bg-depth=1 \ >>> /home/vmuser/scratch/source /home/vmuser/scratch/dest >>> FUSE library version: 3.17.0 >>> Creating ring per-core-queue=1 sync-depth=1 async-depth=1 arglen=1052672 >>> dev unique: 2, opcode: INIT (26), nodeid: 0, insize: 104, pid: 0 >>> INIT: 7.40 >>> flags=0x73fffffb >>> max_readahead=0x00020000 >>> INIT: 7.40 >>> flags=0x4041f429 >>> max_readahead=0x00020000 >>> max_write=0x00100000 >>> max_background=0 >>> congestion_threshold=0 >>> time_gran=1 >>> unique: 2, success, outsize: 80 >>> >>> I created the source and dest folders which are both empty. >>> >>> I see the following in dmesg: >>> >>> [ 2453.197510] uring is disabled >>> [ 2453.198525] uring is disabled >>> [ 2453.198749] uring is disabled >>> ... >>> >>> If I then try to list the directory /home/vmuser/scratch: >>> >>> $ ls -l /home/vmuser/scratch >>> ls: cannot access 'dest': Software caused connection abort >>> >>> And passthrough_hp terminates. >>> >>> My kconfig: >>> >>> CONFIG_FUSE_FS=m >>> CONFIG_FUSE_PASSTHROUGH=y >>> CONFIG_FUSE_IO_URING=y >>> >>> I'll look into it next week but, do you see anything obviously wrong? >> >> >> thanks for testing it! I just pushed a fix to my libfuse branches to >> avoid the abort for -EOPNOTSUPP. It will gracefully fall back to >> /dev/fuse IO now. >> >> Could you please use the rfcv4 branch, as the plain uring >> branch will soon get incompatible updates for rfc5? >> >> https://github.com/bsbernd/libfuse/tree/uring-for-rfcv4 >> >> >> The short answer to let you enable fuse-io-uring: >> >> echo 1 >/sys/module/fuse/parameters/enable_uring >> >> >> (With that the "uring is disabled" should be fixed.) > > Thanks, using this branch fixed the issue and now I can see the dest > folder mirroring that of the source folder. There are two issues I > noticed: > > [63490.068211] ---[ end trace 0000000000000000 ]--- > [64010.242963] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:330 > [64010.243531] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 11057, name: fuse-ring-1 > [64010.244092] preempt_count: 1, expected: 0 > [64010.244346] RCU nest depth: 0, expected: 0 > [64010.244599] 2 locks held by fuse-ring-1/11057: > [64010.244886] #0: ffff888105db20a8 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_enter+0x900/0xd80 > [64010.245476] #1: ffff88810f941818 (&fc->lock){+.+.}-{2:2}, at: fuse_uring_cmd+0x83e/0x1890 [fuse] > [64010.246031] CPU: 1 UID: 0 PID: 11057 Comm: fuse-ring-1 Tainted: G W 6.11.0-10089-g0d2090ccdbbe #2 > [64010.246655] Tainted: [W]=WARN > [64010.246853] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 > [64010.247542] Call Trace: > [64010.247705] <TASK> > [64010.247860] dump_stack_lvl+0xb0/0xd0 > [64010.248090] __might_resched+0x2f8/0x510 > [64010.248338] __kmalloc_cache_noprof+0x2aa/0x390 > [64010.248614] ? lockdep_init_map_type+0x2cb/0x7b0 > [64010.248923] ? fuse_uring_cmd+0xcc2/0x1890 [fuse] > [64010.249215] fuse_uring_cmd+0xcc2/0x1890 [fuse] > [64010.249506] io_uring_cmd+0x214/0x500 > [64010.249745] io_issue_sqe+0x588/0x1810 > [64010.249999] ? __pfx_io_issue_sqe+0x10/0x10 > [64010.250254] ? io_alloc_async_data+0x88/0x120 > [64010.250516] ? io_alloc_async_data+0x88/0x120 > [64010.250811] ? io_uring_cmd_prep+0x2eb/0x9f0 > [64010.251103] io_submit_sqes+0x796/0x1f80 > [64010.251387] __do_sys_io_uring_enter+0x90a/0xd80 > [64010.251696] ? do_user_addr_fault+0x26f/0xb60 > [64010.251991] ? __pfx___do_sys_io_uring_enter+0x10/0x10 > [64010.252333] ? __up_read+0x3ba/0x750 > [64010.252565] ? __pfx___up_read+0x10/0x10 > [64010.252868] do_syscall_64+0x68/0x140 > [64010.253121] entry_SYSCALL_64_after_hwframe+0x76/0x7e > [64010.253444] RIP: 0033:0x7f03a03fb7af > [64010.253679] Code: 45 0f b6 90 d0 00 00 00 41 8b b8 cc 00 00 00 45 31 c0 41 b9 08 00 00 00 41 83 e2 01 41 c1 e2 04 41 09 c2 b8 aa 01 00 00 0f 05 <c3> a8 02 74 cc f0 48 83 0c 24 00 49 8b 40 20 8b 00 a8 01 74 bc b8 > [64010.254801] RSP: 002b:00007f039f3ffd08 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa > [64010.255261] RAX: ffffffffffffffda RBX: 0000561ab7c1ced0 RCX: 00007f03a03fb7af > [64010.255695] RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000009 > [64010.256127] RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000008 > [64010.256556] R10: 0000000000000000 R11: 0000000000000246 R12: 0000561ab7c1d7a8 > [64010.256990] R13: 0000561ab7c1da00 R14: 0000561ab7c1d520 R15: 0000000000000001 > [64010.257442] </TASK> Regarding issue one, does this patch solve it? diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c index e518d4379aa1..304919bc12fb 100644 --- a/fs/fuse/dev_uring.c +++ b/fs/fuse/dev_uring.c @@ -168,6 +168,12 @@ static struct fuse_ring_queue *fuse_uring_create_queue(struct fuse_ring *ring, queue = kzalloc(sizeof(*queue), GFP_KERNEL_ACCOUNT); if (!queue) return ERR_PTR(-ENOMEM); + pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); + if (!pq) { + kfree(queue); + return ERR_PTR(-ENOMEM); + } + spin_lock(&fc->lock); if (ring->queues[qid]) { spin_unlock(&fc->lock); @@ -186,11 +192,6 @@ static struct fuse_ring_queue *fuse_uring_create_queue(struct fuse_ring *ring, INIT_LIST_HEAD(&queue->ent_in_userspace); INIT_LIST_HEAD(&queue->fuse_req_queue); - pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); - if (!pq) { - kfree(queue); - return ERR_PTR(-ENOMEM); - } queue->fpq.processing = pq; fuse_pqueue_init(&queue->fpq); I think we don't need GFP_ATOMIC, but can do allocations before taking the lock. This pq allocation is new in v4 and I forgot to put it into the right place and it slipped through my very basic testing (I'm concentrating on the design changes for now - testing will come back with v6). > > If I am already in dest when I do the mount using passthrough_hp and > then e.g. ls, it hangs indefinitely even if I kill passthrough_hp. I'm going to check in a bit. I hope it is not a recursion issue. Thanks, Bernd
On 10/22/24 12:24, Bernd Schubert wrote: > On 10/21/24 22:57, David Wei wrote: >> If I am already in dest when I do the mount using passthrough_hp and >> then e.g. ls, it hangs indefinitely even if I kill passthrough_hp. > > I'm going to check in a bit. I hope it is not a recursion issue. > Hmm, I cannot reproduce this bernd@squeeze1 dest>pwd /scratch/dest bernd@squeeze1 dest>/home/bernd/src/libfuse/github//build-debian/example/passthrough_hp -o allow_other --nopassthrough --uring --uring-per-core-queue --uring-fg-depth=1 --uring-bg-depth=1 /scratch/source /scratch/dest bernd@squeeze1 dest>ll total 6.4G drwxr-xr-x 2 fusetests fusetests 4.0K Jul 30 17:59 scratch_mnt drwxr-xr-x 2 fusetests fusetests 4.0K Jul 30 17:59 test_dir -rw-r--r-- 1 bernd bernd 50G Sep 12 14:20 testfile -rwxr-xr-x 1 bernd bernd 6.3G Sep 12 14:39 testfile1 Same when running in foreground and doing operations from another console cqe unique: 4, opcode: GETATTR (3), nodeid: 1, insize: 16, pid: 732 unique: 4, result=104 cqe unique: 6, opcode: STATFS (17), nodeid: 1, insize: 0, pid: 732 unique: 6, result=80 In order to check it is not a recursion issue I also switched my VM to one core - still no issue. What is your setup? Also, I'm still on 6.10, I want to send out v5 with separated headers later this week and next week v6 (and maybe without RFC) for 6.12 next week. Thanks, Bernd
On 2024-10-22 05:46, Bernd Schubert wrote: > > > On 10/22/24 12:24, Bernd Schubert wrote: >> On 10/21/24 22:57, David Wei wrote: >>> If I am already in dest when I do the mount using passthrough_hp and >>> then e.g. ls, it hangs indefinitely even if I kill passthrough_hp. >> >> I'm going to check in a bit. I hope it is not a recursion issue. >> > > Hmm, I cannot reproduce this > > bernd@squeeze1 dest>pwd > /scratch/dest > > bernd@squeeze1 dest>/home/bernd/src/libfuse/github//build-debian/example/passthrough_hp -o allow_other --nopassthrough --uring --uring-per-core-queue --uring-fg-depth=1 --uring-bg-depth=1 /scratch/source /scratch/dest > > bernd@squeeze1 dest>ll > total 6.4G > drwxr-xr-x 2 fusetests fusetests 4.0K Jul 30 17:59 scratch_mnt > drwxr-xr-x 2 fusetests fusetests 4.0K Jul 30 17:59 test_dir > -rw-r--r-- 1 bernd bernd 50G Sep 12 14:20 testfile > -rwxr-xr-x 1 bernd bernd 6.3G Sep 12 14:39 testfile1 > > > Same when running in foreground and doing operations from another console > > > cqe unique: 4, opcode: GETATTR (3), nodeid: 1, insize: 16, pid: 732 > unique: 4, result=104 > cqe unique: 6, opcode: STATFS (17), nodeid: 1, insize: 0, pid: 732 > unique: 6, result=80 > > > In order to check it is not a recursion issue I also switched my VM to > one core - still no issue. What is your setup? > Also, I'm still on 6.10, I want to send out v5 with separated headers > later this week and next week v6 (and maybe without RFC) for 6.12 next > week. I tried this again and could not repro anymore. I think your latest libfuse that falls back to /dev/fuse fixed it. Sorry for the noise! > > > Thanks, > Bernd
On 2024-10-22 03:24, Bernd Schubert wrote: > > > On 10/21/24 22:57, David Wei wrote: >> On 2024-10-21 04:47, Bernd Schubert wrote: >>> Hi David, >>> >>> On 10/21/24 06:06, David Wei wrote: >>>> [You don't often get email from dw@davidwei.uk. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] >>>> >>>> On 2024-10-15 17:05, Bernd Schubert wrote: >>>> [...] >>>>> >>> >>> ... >>> >>>> Hi Bernd, I applied this patchset to io_uring-6.12 branch with some >>>> minor conflicts. I'm running the following command: >>>> >>>> $ sudo ./build/example/passthrough_hp -o allow_other --debug-fuse --nopassthrough \ >>>> --uring --uring-per-core-queue --uring-fg-depth=1 --uring-bg-depth=1 \ >>>> /home/vmuser/scratch/source /home/vmuser/scratch/dest >>>> FUSE library version: 3.17.0 >>>> Creating ring per-core-queue=1 sync-depth=1 async-depth=1 arglen=1052672 >>>> dev unique: 2, opcode: INIT (26), nodeid: 0, insize: 104, pid: 0 >>>> INIT: 7.40 >>>> flags=0x73fffffb >>>> max_readahead=0x00020000 >>>> INIT: 7.40 >>>> flags=0x4041f429 >>>> max_readahead=0x00020000 >>>> max_write=0x00100000 >>>> max_background=0 >>>> congestion_threshold=0 >>>> time_gran=1 >>>> unique: 2, success, outsize: 80 >>>> >>>> I created the source and dest folders which are both empty. >>>> >>>> I see the following in dmesg: >>>> >>>> [ 2453.197510] uring is disabled >>>> [ 2453.198525] uring is disabled >>>> [ 2453.198749] uring is disabled >>>> ... >>>> >>>> If I then try to list the directory /home/vmuser/scratch: >>>> >>>> $ ls -l /home/vmuser/scratch >>>> ls: cannot access 'dest': Software caused connection abort >>>> >>>> And passthrough_hp terminates. >>>> >>>> My kconfig: >>>> >>>> CONFIG_FUSE_FS=m >>>> CONFIG_FUSE_PASSTHROUGH=y >>>> CONFIG_FUSE_IO_URING=y >>>> >>>> I'll look into it next week but, do you see anything obviously wrong? >>> >>> >>> thanks for testing it! I just pushed a fix to my libfuse branches to >>> avoid the abort for -EOPNOTSUPP. It will gracefully fall back to >>> /dev/fuse IO now. >>> >>> Could you please use the rfcv4 branch, as the plain uring >>> branch will soon get incompatible updates for rfc5? >>> >>> https://github.com/bsbernd/libfuse/tree/uring-for-rfcv4 >>> >>> >>> The short answer to let you enable fuse-io-uring: >>> >>> echo 1 >/sys/module/fuse/parameters/enable_uring >>> >>> >>> (With that the "uring is disabled" should be fixed.) >> >> Thanks, using this branch fixed the issue and now I can see the dest >> folder mirroring that of the source folder. There are two issues I >> noticed: >> >> [63490.068211] ---[ end trace 0000000000000000 ]--- >> [64010.242963] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:330 >> [64010.243531] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 11057, name: fuse-ring-1 >> [64010.244092] preempt_count: 1, expected: 0 >> [64010.244346] RCU nest depth: 0, expected: 0 >> [64010.244599] 2 locks held by fuse-ring-1/11057: >> [64010.244886] #0: ffff888105db20a8 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_enter+0x900/0xd80 >> [64010.245476] #1: ffff88810f941818 (&fc->lock){+.+.}-{2:2}, at: fuse_uring_cmd+0x83e/0x1890 [fuse] >> [64010.246031] CPU: 1 UID: 0 PID: 11057 Comm: fuse-ring-1 Tainted: G W 6.11.0-10089-g0d2090ccdbbe #2 >> [64010.246655] Tainted: [W]=WARN >> [64010.246853] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 >> [64010.247542] Call Trace: >> [64010.247705] <TASK> >> [64010.247860] dump_stack_lvl+0xb0/0xd0 >> [64010.248090] __might_resched+0x2f8/0x510 >> [64010.248338] __kmalloc_cache_noprof+0x2aa/0x390 >> [64010.248614] ? lockdep_init_map_type+0x2cb/0x7b0 >> [64010.248923] ? fuse_uring_cmd+0xcc2/0x1890 [fuse] >> [64010.249215] fuse_uring_cmd+0xcc2/0x1890 [fuse] >> [64010.249506] io_uring_cmd+0x214/0x500 >> [64010.249745] io_issue_sqe+0x588/0x1810 >> [64010.249999] ? __pfx_io_issue_sqe+0x10/0x10 >> [64010.250254] ? io_alloc_async_data+0x88/0x120 >> [64010.250516] ? io_alloc_async_data+0x88/0x120 >> [64010.250811] ? io_uring_cmd_prep+0x2eb/0x9f0 >> [64010.251103] io_submit_sqes+0x796/0x1f80 >> [64010.251387] __do_sys_io_uring_enter+0x90a/0xd80 >> [64010.251696] ? do_user_addr_fault+0x26f/0xb60 >> [64010.251991] ? __pfx___do_sys_io_uring_enter+0x10/0x10 >> [64010.252333] ? __up_read+0x3ba/0x750 >> [64010.252565] ? __pfx___up_read+0x10/0x10 >> [64010.252868] do_syscall_64+0x68/0x140 >> [64010.253121] entry_SYSCALL_64_after_hwframe+0x76/0x7e >> [64010.253444] RIP: 0033:0x7f03a03fb7af >> [64010.253679] Code: 45 0f b6 90 d0 00 00 00 41 8b b8 cc 00 00 00 45 31 c0 41 b9 08 00 00 00 41 83 e2 01 41 c1 e2 04 41 09 c2 b8 aa 01 00 00 0f 05 <c3> a8 02 74 cc f0 48 83 0c 24 00 49 8b 40 20 8b 00 a8 01 74 bc b8 >> [64010.254801] RSP: 002b:00007f039f3ffd08 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa >> [64010.255261] RAX: ffffffffffffffda RBX: 0000561ab7c1ced0 RCX: 00007f03a03fb7af >> [64010.255695] RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000009 >> [64010.256127] RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000008 >> [64010.256556] R10: 0000000000000000 R11: 0000000000000246 R12: 0000561ab7c1d7a8 >> [64010.256990] R13: 0000561ab7c1da00 R14: 0000561ab7c1d520 R15: 0000000000000001 >> [64010.257442] </TASK> > > Regarding issue one, does this patch solve it? > > diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c > index e518d4379aa1..304919bc12fb 100644 > --- a/fs/fuse/dev_uring.c > +++ b/fs/fuse/dev_uring.c > @@ -168,6 +168,12 @@ static struct fuse_ring_queue *fuse_uring_create_queue(struct fuse_ring *ring, > queue = kzalloc(sizeof(*queue), GFP_KERNEL_ACCOUNT); > if (!queue) > return ERR_PTR(-ENOMEM); > + pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); > + if (!pq) { > + kfree(queue); > + return ERR_PTR(-ENOMEM); > + } > + > spin_lock(&fc->lock); > if (ring->queues[qid]) { > spin_unlock(&fc->lock); > @@ -186,11 +192,6 @@ static struct fuse_ring_queue *fuse_uring_create_queue(struct fuse_ring *ring, > INIT_LIST_HEAD(&queue->ent_in_userspace); > INIT_LIST_HEAD(&queue->fuse_req_queue); > > - pq = kcalloc(FUSE_PQ_HASH_SIZE, sizeof(struct list_head), GFP_KERNEL); > - if (!pq) { > - kfree(queue); > - return ERR_PTR(-ENOMEM); > - } > queue->fpq.processing = pq; > fuse_pqueue_init(&queue->fpq); > > > I think we don't need GFP_ATOMIC, but can do allocations before taking > the lock. This pq allocation is new in v4 and I forgot to put it into > the right place and it slipped through my very basic testing (I'm > concentrating on the design changes for now - testing will come back > with v6). Thanks, this patch fixed it for me. > >> >> If I am already in dest when I do the mount using passthrough_hp and >> then e.g. ls, it hangs indefinitely even if I kill passthrough_hp. > > I'm going to check in a bit. I hope it is not a recursion issue. > > > Thanks, > Bernd
On 2024-10-15 17:05, Bernd Schubert wrote: > RFCv1 and RFCv2 have been tested with multiple xfstest runs in a VM > (32 cores) with a kernel that has several debug options > enabled (like KASAN and MSAN). RFCv3 is not that well tested yet. > O_DIRECT is currently not working well with /dev/fuse and > also these patches, a patch has been submitted to fix that (although > the approach is refused) > https://www.spinics.net/lists/linux-fsdevel/msg280028.html Hi Bernd, I applied this patch and the associated libfuse patch at: https://github.com/bsbernd/libfuse/tree/aligned-writes I have a simple Python FUSE client that is still returning EINVAL for write(): with open(sys.argv[1], 'r+b') as f: mmapped_file = mmap.mmap(f.fileno(), 0) shm = shared_memory.SharedMemory(create=True, size=mmapped_file.size()) shm.buf[:mmapped_file.size()] = mmapped_file[:] fd = os.open("/home/vmuser/scratch/dest/out", O_RDWR|O_CREAT|O_DIRECT) with open(fd, 'w+b') as f2: f2.write(bytes(shm.buf)) mmapped_file.close() shm.unlink() shm.close() I'll keep looking at this but letting you know in case it's something obvious again.
This adds support for uring communication between kernel and userspace daemon using opcode the IORING_OP_URING_CMD. The basic appraoch was taken from ublk. The patches are in RFC state, some major changes are still to be expected. Motivation for these patches is all to increase fuse performance. In fuse-over-io-uring requests avoid core switching (application on core X, processing of fuse server on random core Y) and use shared memory between kernel and userspace to transfer data. Similar approaches have been taken by ZUFS and FUSE2, though not over io-uring, but through ioctl IOs https://lwn.net/Articles/756625/ https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git/log/?h=fuse2 Avoiding cache line bouncing / numa systems was discussed between Amir and Miklos before and Miklos had posted part of the private discussion here https://lore.kernel.org/linux-fsdevel/CAJfpegtL3NXPNgK1kuJR8kLu3WkVC_ErBPRfToLEiA_0=w3=hA@mail.gmail.com/ This cache line bouncing should be reduced by these patches, as a) Switching between kernel and userspace is reduced by 50%, as the request fetch (by read) and result commit (write) is replaced by a single and submit and fetch command b) Submitting via ring can avoid context switches at all. Note: As of now userspace still needs to transition to the kernel to wake up the submit the result, though it might be possible to avoid that as well (for example either with IORING_SETUP_SQPOLL (basic testing did not show performance advantage for now) or the task that is submitting fuse requests to the ring could also poll for results (needs additional work). I had also noticed waitq wake-up latencies in fuse before https://lore.kernel.org/lkml/9326bb76-680f-05f6-6f78-df6170afaa2c@fastmail.fm/T/ This spinning approach helped with performance (>40% improvement for file creates), but due to random server side thread/core utilization spinning cannot be well controlled in /dev/fuse mode. With fuse-over-io-uring requests are handled on the same core (sync requests) or on core+1 (large async requests) and performance improvements are achieved without spinning. Splice/zero-copy is not supported yet, Ming Lei is working on io-uring support for ublk_drv, we can probably also use that approach for fuse and get better zero copy than splice. https://lore.kernel.org/io-uring/20240808162438.345884-1-ming.lei@redhat.com/ RFCv1 and RFCv2 have been tested with multiple xfstest runs in a VM (32 cores) with a kernel that has several debug options enabled (like KASAN and MSAN). RFCv3 is not that well tested yet. O_DIRECT is currently not working well with /dev/fuse and also these patches, a patch has been submitted to fix that (although the approach is refused) https://www.spinics.net/lists/linux-fsdevel/msg280028.html Up the to RFCv2 nice effect in io-uring mode was that xftests run faster (like generic/522 ~2400s /dev/fuse vs. ~1600s patched), though still slow as this is with ASAN/leak-detection/etc. With RFCv3 and removed mmap overall run time as approximately the same, though some optimizations are removed in RFCv3, like submitting to the ring from the task that created the fuse request (hence, without io_uring_cmd_complete_in_task()). The corresponding libfuse patches are on my uring branch, but need cleanup for submission - will happen during the next days. https://github.com/bsbernd/libfuse/tree/uring Testing with that libfuse branch is possible by running something like: example/passthrough_hp -o allow_other --debug-fuse --nopassthrough \ --uring --uring-per-core-queue --uring-fg-depth=1 --uring-bg-depth=1 \ /scratch/source /scratch/dest With the --debug-fuse option one should see CQE in the request type, if requests are received via io-uring: cqe unique: 4, opcode: GETATTR (3), nodeid: 1, insize: 16, pid: 7060 unique: 4, result=104 Without the --uring option "cqe" is replaced by the default "dev" dev unique: 4, opcode: GETATTR (3), nodeid: 1, insize: 56, pid: 7117 unique: 4, success, outsize: 120 TODO list for next RFC version - make the buffer layout exactly the same as /dev/fuse IO - different request size - a large ring queue size currently needs too much memory, even if most of the queue size is needed for small IOs Future work - zero copy I had run quite some benchmarks with linux-6.2 before LSFMMBPF2023, which, resulted in some tuning patches (at the end of the patch series). Benchmark results (with RFC v1) ======================================= System used for the benchmark is a 32 core (HyperThreading enabled) Xeon E5-2650 system. I don't have local disks attached that could do >5GB/s IOs, for paged and dio results a patched version of passthrough-hp was used that bypasses final reads/writes. paged reads ----------- 128K IO size 1024K IO size jobs /dev/fuse uring gain /dev/fuse uring gain 1 1117 1921 1.72 1902 1942 1.02 2 2502 3527 1.41 3066 3260 1.06 4 5052 6125 1.21 5994 6097 1.02 8 6273 10855 1.73 7101 10491 1.48 16 6373 11320 1.78 7660 11419 1.49 24 6111 9015 1.48 7600 9029 1.19 32 5725 7968 1.39 6986 7961 1.14 dio reads (1024K) ----------------- jobs /dev/fuse uring gain 1 2023 3998 2.42 2 3375 7950 2.83 4 3823 15022 3.58 8 7796 22591 2.77 16 8520 27864 3.27 24 8361 20617 2.55 32 8717 12971 1.55 mmap reads (4K) --------------- (sequential, I probably should have made it random, sequential exposes a rather interesting/weird 'optimized' memcpy issue - sequential becomes reversed order 4K read) https://lore.kernel.org/linux-fsdevel/aae918da-833f-7ec5-ac8a-115d66d80d0e@fastmail.fm/ jobs /dev/fuse uring gain 1 130 323 2.49 2 219 538 2.46 4 503 1040 2.07 8 1472 2039 1.38 16 2191 3518 1.61 24 2453 4561 1.86 32 2178 5628 2.58 (Results on request, setting MAP_HUGETLB much improves performance for both, io-uring mode then has a slight advantage only.) creates/s ---------- threads /dev/fuse uring gain 1 3944 10121 2.57 2 8580 24524 2.86 4 16628 44426 2.67 8 46746 56716 1.21 16 79740 102966 1.29 20 80284 119502 1.49 (the gain drop with >=8 cores needs to be investigated) Jens had done some benchmarks with v3 and noticed only 25% improvement and half of CPU time usage, but v3 removes several optimizations (like waking the same core and avoiding task io_uring_cmd_done in extra task context). These optimizations will be submitted once the core work is merged. Remaining TODO list for RFCv3: -------------------------------- 1) Let the ring configure ioctl return information, like mmap/queue-buf size Right now libfuse and kernel have lots of duplicated setup code and any kind of pointer/offset mismatch results in a non-working ring that is hard to debug - probably better when the kernel does the calculations and returns that to server side 2) In combination with 1, ring requests should retrieve their userspace address and length from kernel side instead of calculating it through the mmaped queue buffer on their own. (Introduction of FUSE_URING_BUF_ADDR_FETCH) 3) Add log buffer into the ioctl and ring-request This is to provide better error messages (instead of just errno) 3) Multiple IO sizes per queue Small IOs and metadata requests do not need large buffer sizes, we need multiple IO sizes per queue. 4) FUSE_INTERRUPT handling These are not handled yet, kernel side is probably not difficult anymore as ring entries take fuse requests through lists. TODO: ====== - separate buffer for fuse headers to always handle alignment Signed-off-by: Bernd Schubert <bschubert@ddn.com> --- Changes in v4: - Removal of ioctls, all configuration is done dynamically on the arrival of FUSE_URING_REQ_FETCH - ring entries are not (and cannot be without config ioctls) allocated as array of the ring/queue - removal of the tag variable. Finding ring entries on FUSE_URING_REQ_COMMIT_AND_FETCH is more cumbersome now and needs an almost unused struct fuse_pqueue per fuse_ring_queue and uses the unique id of fuse requests. - No device clones needed for to workaroung hanging mounts on fuse-server/daemon termination, handled by IO_URING_F_CANCEL - Removal of sync/async ring entry types - Addressed some of Joannes comments, but probably not all - Only very basic tests run for v3, as more updates should follow quickly. Changes in v3 - Removed the __wake_on_current_cpu optimization (for now as that needs to go through another subsystem/tree) , removing it means a significant performance drop) - Removed MMAP (Miklos) - Switched to two IOCTLs, instead of one ioctl that had a field for subcommands (ring and queue config) (Miklos) - The ring entry state is a single state and not a bitmask anymore (Josef) - Addressed several other comments from Josef (I need to go over the RFCv2 review again, I'm not sure if everything is addressed already) - Link to v3: https://lore.kernel.org/r/20240901-b4-fuse-uring-rfcv3-without-mmap-v3-0-9207f7391444@ddn.com - Link to v2: https://lore.kernel.org/all/20240529-fuse-uring-for-6-9-rfc2-out-v1-0-d149476b1d65@ddn.com/ - Link to v1: https://lore.kernel.org/r/20240529-fuse-uring-for-6-9-rfc2-out-v1-0-d149476b1d65@ddn.com --- Bernd Schubert (14): fuse: rename to fuse_dev_end_requests and make non-static fuse: Move fuse_get_dev to header file fuse: Move request bits fuse: Add fuse-io-uring design documentation fuse: {uring} Handle SQEs - register commands fuse: Make fuse_copy non static fuse: Add buffer offset for uring into fuse_copy_state fuse: {uring} Add uring sqe commit and fetch support fuse: {uring} Handle teardown of ring entries fuse: {uring} Add a ring queue and send method fuse: {uring} Allow to queue to the ring fuse: {uring} Handle IO_URING_F_TASK_DEAD fuse: {io-uring} Prevent mount point hang on fuse-server termination fuse: enable fuse-over-io-uring Pavel Begunkov (1): io_uring/cmd: let cmds to know about dying task Documentation/filesystems/fuse-io-uring.rst | 101 +++ fs/fuse/Kconfig | 12 + fs/fuse/Makefile | 1 + fs/fuse/dev.c | 155 ++-- fs/fuse/dev_uring.c | 1130 +++++++++++++++++++++++++++ fs/fuse/dev_uring_i.h | 199 +++++ fs/fuse/fuse_dev_i.h | 64 ++ fs/fuse/fuse_i.h | 14 + fs/fuse/inode.c | 5 +- include/linux/io_uring_types.h | 1 + include/uapi/linux/fuse.h | 70 ++ io_uring/uring_cmd.c | 6 +- 12 files changed, 1706 insertions(+), 52 deletions(-) --- base-commit: 0c3836482481200ead7b416ca80c68a29cfdaabd change-id: 20241015-fuse-uring-for-6-10-rfc4-61d0fc6851f8 Best regards,